Menu
Home
People
Places
Arts
History
Plants & Animals
Science
Life & Culture
Technology
Reference.org
Stellar kinematics
open-in-new
<p>In <a href="/facts/Astronomy/0ArJVM1p">astronomy</a>, stellar kinematics is the <a href="/facts/Observational_astronomy/PKgYt9PX">observational</a> study or measurement of the <a href="/facts/Kinematics/o7mSyeJA">kinematics</a> or motions of <a href="/facts/Star/PFbd6ICx">stars</a> through space. </p><p>Stellar kinematics encompasses the measurement of stellar <a href="/facts/Velocity/Q3o1LVDe">velocities</a> in the <a href="/facts/Milky_Way/ulF6lccN">Milky Way</a> and its <a href="/facts/Satellite_galaxies_of_the_Milky_Way/eJEwRM6g">satellites</a> as well as the internal kinematics of more distant <a href="/facts/Galaxy/zCyUvEf7">galaxies</a>. Measurement of the kinematics of stars in different subcomponents of the Milky Way including the <a href="/facts/Thin_disk/1jC1mmU0">thin disk</a>, the <a href="/facts/Thick_disk/Lez3T9oW">thick disk</a>, the <a href="/facts/Bulge_(astronomy)/cjJ0LFan">bulge</a>, and the <a href="/facts/Stellar_halo/tBr2th1p">stellar halo</a> provides important information about the formation and evolutionary history of our Galaxy. Kinematic measurements can also identify exotic phenomena such as hypervelocity stars escaping from the Milky Way, which are interpreted as the result of gravitational encounters of <a href="/facts/Binary_star/TYlDe1bD">binary stars</a> with the <a href="/facts/Sagittarius_A*/5TWIRfgm">supermassive black hole at the Galactic Center</a>. </p><p>Stellar kinematics is related to but distinct from the subject of <a href="/facts/Stellar_dynamics/TTqAf5M1">stellar dynamics</a>, which involves the theoretical study or modeling of the motions of stars under the influence of <a href="/facts/Gravity/bqAN7DdQ">gravity</a>. Stellar-dynamical models of systems such as galaxies or star clusters are often compared with or tested against stellar-kinematic data to study their evolutionary history and mass distributions, and to detect the presence of <a href="/facts/Dark_matter/y5HgX55N">dark matter</a> or <a href="/facts/Supermassive_black_hole/BcuTx8Q5">supermassive black holes</a> through their gravitational influence on stellar orbits. </p>